Phylogeny and Diversification of Araliales

楤木目的系统发育和多样化

• 批准号: 9981641
• 负责人: Gregory Plunkett
• 金额: $ 20万
• 依托单位: Virginia Commonwealth University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-03-15 至 2004-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9981641&HistoricalAwards=false
• 关键词: Phylogeny; Diversification; Araliales

9981641Plunkett and Lowry Two investigators, the first a young scientist with expertise in molecular systematics and impressive publications from his dissertation studies and the second an experienced field naturalist and plant monographer, are combining forces to study the large, mostly southern hemisphere plant family Araliaceae and its close relatives, to improve taxonomic classification of the group, construct a framework phylogeny for the genera, and begin to determine the historical biogeography that accounts for the current widespread distribution of these plants. The Araliaceae are the predominantly tropical relatives of the mostly temperate-zone carrot family, the Apiaceae or Umbelliferae. Araliaceae include numerous small (1-25 species) genera, and two huge genera, Schefflera (with ca. 650 described species) and Polyscias (with ca. 150 species). With Apiaceae and the Old World tropical family Pittosporaceae, the Araliaceae constitute the order Araliales, along with four difficult-to-place genera: Aralidium (western Malesia), Griselinia (disjunct in Chile and New Zealand), Melanophylla (Madagascar), and Toricellia (the Himalayas). Traditional morphological characters, useful in species-level discrimination, have proved unreliable in delimiting sublineages within the group, but preliminary DNA sequence data show evidence of resolving the major lineages and many sublineages within Araliales. With extensive samples already accumulated, in large part due to Lowry's personal field collecting and contacts with colleagues worldwide, and to be supplemented with targeted field work in Asia and Australasia, new data will be collected for nuclear and chloroplast genes, in order to assess mutational differences at species, genus, and family levels throughout the group. Selected anatomical, chromosomal, and morphological characters will be integrated to bolster phylogenetic resolution and improve generic classification. With a reliable phylogenetic framework in place, the investigators can begin to unravel the historical pathways of migration and diversification that have resulted in the current distribution of the group. A few aralialean fossils suggest Cretaceous origins for the group, consistent with an early "Gondwanan" distribution pattern, and subsequent expansions on all the southern hemisphere continents. Further insights rely upon successful resolution of the phylogenetic relationships of the genera, in turn upon careful taxonomic sampling of the known geographic and morphological variation in Araliales.

9981641 Plunkett和Lowry两位研究人员，第一位是具有分子系统学专业知识的年轻科学家，他的论文研究成果令人印象深刻，第二位是经验丰富的野外博物学家和植物专著作者，他们正在联合力量研究主要位于南半球的大型植物科五加科及其近亲，以改进该组的分类学分类，构建属的系统发育框架，并开始确定这些植物目前广泛分布的历史地理。五加科主要是温带胡萝卜科、伞形科或伞形科的热带亲戚。五加科包括许多小属（1-25种），和两个巨大的属，鹅掌柴属（与ca。650描述的物种）和Polyscias（约。150种）。五加科与伞形科和旧大陆热带海桐科一起构成五加目，沿着有四个难以定位的属：五加属（马来群岛西部）、灰叶木属（智利和新西兰间断分布）、黑叶木属（马达加斯加）和托丽夏属（喜马拉雅山脉）。传统的形态特征，有用的物种水平的歧视，已被证明是不可靠的划定亚系内的组，但初步的DNA序列数据显示的证据，解决主要的血统和许多亚系内五加目。随着大量的样本已经积累，在很大程度上是由于洛瑞的个人现场收集和与世界各地的同事联系，并补充有针对性的实地工作在亚洲和澳大拉西亚，新的数据将收集核和叶绿体基因，以评估突变的差异在物种，属，和家庭的水平在整个组。选定的解剖，染色体和形态特征将被整合，以支持系统发育的分辨率和提高属的分类。有了一个可靠的系统发育框架，研究人员可以开始解开导致该群体目前分布的迁移和多样化的历史途径。一些阿拉利亚人的化石表明该群体起源于白垩纪，与早期的冈瓦纳分布模式相一致，随后在南半球的所有大陆上扩张。进一步的见解依赖于成功的解决属的系统发育关系，反过来又仔细分类采样已知的地理和形态变异的五加目。